UNITING THE BUILT & NATURAL ENVIRONMENTS

The National Building Museum hosted a tour of the new U.S. Capitol Visitor Center, a $600 million-plus, 580,000-square foot exhibition hall, learning center, and events space designed by architecture firm RTKL. The high costs were caused by the expanded scope of the project (there were more than 3,000 changes to the initial project) and heavy security requirements needed after 9/11 and the shooting of two Capitol Hill police officers. Of the more than 580,000 square feet of space, only a third is open to the public. The other two-thirds includes new space for storage, infrastructure, and security, and offices only available to Capitol Hill representatives and their staffers.

The Visitor Center required digging 70-feet into the earth. Excavating the 5-acre site involved moving 53,000 truckloads of Potomac clay soil. Due to the local clay soil, which doesn’t absorb water well, lakes formed where digging had occured, attracting migrating geese and other birds. Tom Fontana, director of communications for the Visitor Center, said “we were afraid the dig site would be declared a wetland.”

Much of the original Capitol was built with slave labor, and, as a result, the central hall is called “Emancipation Hall.” Heavy security almost meant the removal of the skylights that bring natural light into Emancipation Hall and give visitors unique views of the Capitol dome. “After 9/11, there was a move towards removing the skylights from the plan — they were viewed as a security breach. After several re-designs, they discovered they needed to preserve views of the Capitol if they were going to avoid creating a bunker feeling,” said Fontana. Additionally, the dense, multi-layered glass was specially re-designed to withstand pedestrian bombs or the weight of an SUV. “The glass will shatter not scatter” if there is an attack.

The interior of the new building definitely feels like Fort Knox in places. There is more than 200,000 square feet of sandstone from a quarry in Western Pennsylvania, which helps create the extra-solid feel. “We used stone that has inconsistencies, imperfections, stone that would have been rejected by many buildings.” This is because the stone used in the original Capitol buldings also include flaws.

Some of the expanded costs can be linked to issues relocating historic trees and fitting members’ parking spaces into the new design. “We spent $30 million clearing the grounds and relocating trees planted by Congressional representatives or Presidents.” These historic trees “couldn’t have just been turned into pencils” but had to uprooted and moved. “We spent $40,000 moving one historic tree one hundred feet.” One key Capitol Hill staffer also almost held up the project because her car, which wouldn’t be moved from its pre-assigned place, was getting dusty from all the construction work.

Updating the air systems to handle anthrax attacks required an additional $40 million. Air systems had to be moved to secure locations deep within the building, and air is now funneled from somewhere on the top of the Capitol dome into the building at a rate of 60 miles per hour.

In terms of design, some of the more interesting elements in the new spaces were inspired by Frederick Law Olmsted, who designed the original Capitol Hill landscape architecture, and his use of natural rock face in some walls. “Olmsted saw nature on the site as a respite from the city’s colossal structures.”

There was controversy about what the new Visitor Center would do to Olmsted’s original vision. Olmsted removed some 400 trees to create the axis on site and leave clear views of the Capitol building, accessible via paths that slow access to the main building. “Olmsted’s original plan broke the tyranny of the grid, creating arcing paths. You can see similar designs on Yale and Stanford’s campuses.”

To preserve his original designs, Olmsted-related societies and other historic preservation groups got involved, asking the Capitol design team to insert minimal “slits” for escalators that would then gradually bring visitors down into the center. Instead, the new designs cut two deep and relatively wide troughs leading to the center. Olmsted’s “teardrop” ovals remain intact though, making any procession to the Capitol intentionally slow (as was originally designed). Additionally, the pedestrian plaza is now framed by rails, benches and lighting details from the original 1840’s design.

Fontana concluded that if the design alters the original Olmsted plan, it keeps to its intentions by keeping the focus on the Capitol and preserving access. Also, “aspects of the original Olmsted plan were never even realized.”